Roman Numerals Converter
Convert between Arabic numbers and Roman numerals instantly. Bidirectional converter supports 1-3999. Perfect for historical dates, clock faces, book chapters, and educational purposes.
- No data sent to server
- Works completely offline
- Instant conversion
- No login or signup needed
How It Works
Enter a regular number (1-3999) to convert to Roman numerals, or enter Roman numerals to convert to Arabic numbers. The conversion happens instantly as you type. Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation is used (IV=4, IX=9, XL=40, XC=90, CD=400, CM=900). The tool validates input and shows common examples like years, chapter numbers, and clock numerals. Perfect for historical dates, Roman numeral clocks, book chapters, movie credits, or learning Roman numeral system. All conversion happens in your browser using standard Roman numeral rules.
Frequently Asked Questions
What numbers can be converted?
1 to 3999. Roman numerals don't have a symbol for zero or numbers above 3999 (MMMCMXCIX).
What do the letters mean?
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Smaller value before larger = subtract (IV=4). Same or larger after = add (VI=6).
How does subtractive notation work?
When a smaller numeral appears before a larger one, subtract it: IV=4 (5-1), IX=9 (10-1), XL=40 (50-10), XC=90 (100-10).
Can I convert years?
Yes! Perfect for historical dates. For example, 2024 converts to MMXXIV.
Are Roman numerals case-sensitive?
No. Enter uppercase (XIV) or lowercase (xiv) - both work. The converter displays uppercase.